Does anyone know if isolation valves on a multiple chiller plant are required by ASHRAE, or they simply best practice?
I have looked into this in ASHRAE documents, but have not found anything yet. I do know for a fact that a non-operating chiller will pass water without cooling it and eventually mix with the cooled water leaving the operating chiller producing a mixed chilled water temperature that will be higher than setpoint to the load (proportional to the flows of each chiller).
I obviously get resistance from the installing contractors due to monetary issues.
Thanks
Jorge
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Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
January 26, 2017 - 3:44 pm
I do not think you will find this requirement in a standard but installing isolation valves is more than best practice, it is the standard of care. I have never heard of a contractor pushing back on isolation valves! Isolation valves are not just required to save energy, they are needed for basic maintenance. What if you need your chiller plant but have one chiller go down? Also, do you drain the whole system just so you can clean condenser and evaporator bundles? Isolation valves are just part of doing business for any hydronic system.